mod(taskwarrior): complete push implementation

Currently the merging process is not working entirely as I would
expect. There are no checks for actual changes between the local version
and the server version. WIP for #3. Configuration file created with
corresponding values like, user name and access code, which are - for
obvious reasons - not commited.

cmd/gitw/main.go

@@ -10,7 +10,7 @@ import (
 
 func main() {
 	// TODO: server url may be also be derived from the git configuration?
-	server := gitea.NewGitea("https://gitea.yves-biener.de")
+	server := gitea.NewGitea()
 	repository, err := gitw.Discover()
 	if err != nil {
 		fmt.Fprintln(os.Stderr, err)